1. Field of the Invention
This invention relates to a case for holding two compact discs, or the like. The term compact disc (CD) as used herein refers to digitally encoded optical discs, particularly but not exclusively video, audio or CD-ROM discs. Such discs are made in several diameter sizes, the most common of which is 12 cm.
2. Description of Background Art
An industrial standard has already been established for the dimensions and configurations of CDs, cases for holding single CDs and cases for holding double CDs. In general all CD manufacturers produce CD cases within the parameters of the industrial standard so that their products can be used for holding standard size CDs, be easily displayed on display shelves in shops, and can accommodate the insertion of printed inserts of standard formats. This also allows end customers to conveniently store the cases with other CDs in their collections.
A conventional double CD case has the same dimensions as those of a single CD case except that its depth or thickness is slightly more than double that of the single CD case. The standard thickness of a single CD case is about 10 mm (as measured from front to rear when the case is closed), whereas the standard thickness of a double CD case is about 24 mm. For the manufacturer, the larger size means increased manufacturing and transportation costs, and for the consumer the larger size means that more storage space is required. Furthermore, conventional storage racks for storing single CDs are not suitably adapted for holding double CD cases to allow a mixture of single and double CD cases to be stored in the same rack.
Double CD cases which have the same external dimensions as a standard single CD case are known in the art, but these designs suffer from other drawbacks.
For example, EP-A-0420350 describes a case which has a front or top lid swivellably attached to one edge of an intermediate part, and a rear or bottom lid swivellably attached to another edge of the intermediate part at the opposite end of the intermediate part to the first edge. When the lids are both opened, the case forms a zig-zag shape. However, such a case requires a special type of printed insert to be used because the standard format for printed inserts for a conventional single CD case will not fit. The conventional insert format comprises a fairly elaborate front-cover leaflet with several pages describing the contents and the performers, to be inserted on the inside of the top lid, and a single back-cover sheet of simple description inserted on the inside of the bottom lid. The design and printing of the alternative inserts and the machinery needed to fit the new inserts adds to the costs of manufacture.
Furthermore, in order to achieve the same overall dimensions as a conventional single CD case, the top and bottom lids tend to be thinner and therefore less solid than the conventional single CD case. A further drawback is that since the top and bottom lids are placed in juxta positions, it is necessary to turnover the whole CD case to get the second CD after taking/replacing the first CD.
An alternative design of a relatively thin double CD case is also known in which a tray for carrying the two CDs is hinged to the bottom lid of the case at the opposite end of the case to the hinge connection between the top and bottom lids. With this design, the tray opens outwardly away from the top and bottom lids to give the user access to the CD carried on the underside of the tray. The major problem with this is that when the tray is opened it travels outside the top and bottom lids, and the CD which originally rests on the upper surface of the tray will be suspended upside down outside the case. If the CD is not clamped properly to the tray, it may well drop off and be damaged since it will not be protected by either of the lids.
Furthermore, the arrangement of the discs may be confusing to the user since, when the case is fully opened, the disc originally resting on top of the tray will become the disc underneath the tray, and vica versa.